Circulation (chondrichthyes)?

Question

me and my friend have to do a project on chondrichtheyes and we was wondering could some one give us a nice defintion that could explain circulation that does not some from dictionary .com because we have to explain it, and we was wondering it some one could explain it..

we are freshmens in a biology honors class and we need to add the defintion of circulation in out power point.

thank you

Answer 1

The circulatory system in every fish is closed meaning blood flows within blood vessels. The two chambers in chondrichthyes hearts consist of a thin-walled atrium and a muscular ventricle. The arterial (oxygenated) blood comes from the gills and gains arteries towards tissues, and then venous blood is collected by veins and reaches the atrium of the heart passing to the ventricle that pumps the venous blood towards the gills to be again oxygenated.